WASHINGTON — The Pentagon is bringing back to work at least 90 percent of the estimated 350,000 defense civilian employees who were furloughed in the partial government shutdown. The move takes a big bite out of the impact of the political impasse in Washington that has left the government without a budget.

The decision announced Saturday by Defense Secretary Chuck Hagel is based on a Pentagon interpretation of a law called the Pay Our Military Act. That measure was passed by Congress and signed by President Barack Obama shortly before the partial government shutdown began Tuesday.

Republican lawmakers had complained in recent days that the Obama administration was slow to bring back those workers even though the law allowed it.

In a written statement explaining his action, Hagel said the Justice Department advised that the law does not permit a blanket recall of all Pentagon civilians. But government attorneys concluded that the law does allow the Pentagon to eliminate furloughs for “employees whose responsibilities contribute to the morale, well-being, capabilities and readiness of service members.”

Hagel said he has told Pentagon officials, including leaders of the military services, to “identify all employees whose activities fall under these categories.” He said civilian workers should stand by for further word this weekend.

In remarks to reporters, Robert Hale, the Pentagon’s budget chief, said he did not yet know the exact number of civilians who would be brought back to work but that it would be “90 percent plus.” He said there are about 350,000 civilians on furlough, somewhat fewer than the 400,000 that officials had previously indicated. If 90 percent were recalled that would mean 315,000 coming off furlough.

Hale said that even with this relief, the effect of the furloughs has been severe.

“We’ve seriously harmed civilian morale; this (recall) will be a start back,” he said.

Hale said he hoped that a “substantial number” could be returned to work on Monday but that an exact timetable is not available.

Hagel had made clear earlier in the past week that Pentagon lawyers were trying to determine ways for some of the Defense Department’s furloughed civilians to get back to work.

“It does have an effect on our relationships around the world and it cuts straight to the obvious question,” he told reporters traveling with him Tuesday in South Korea. “Can you rely on the United States as a reliable partner to fulfill its commitments to its allies?”

The law ensured that members of the military, who have remained at work throughout the shutdown, would be paid on time. It also left room for the Pentagon to keep on the job those civilians who provide support to the military.